Organic Fertilizer for Hay Pastures?

Image by Fugue
These bones are to be ground into a fine powder to make bone meal, which will be used in organic fertiliser.

Question by Fishstick: Organic Fertilizer for Hay Pastures?
We’re contemplating using organic fertlizier for our hay pastures this year, but we’re wondering if anyone out there has used it, and how it worked for them. The fertilizer that we usually use is incredibly expensive, and it keeps costing more and more every year, so we’re looking for effective, less expensive options. Obviously a seller will have a biased opinion about their product, so any opinions would be appreciated!
They’re pre-established pastures, and we run cows on them during the winter months, so there’s already manure on them. We typically use 21-8-17 blend, but because of the cost, we’re exploring other options. One option we’ve seen uses a fish and seaweed fertlizer, as well as other compounds to fertlize.

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